[scenario] Add test case to check for RO access

Test if a compute instance with RO access granted to it via floating
IP address fails to write on the share. Also, add the capability to
pass the access level to the methods that allow access to shares.

Change-Id: I1aef8f1ed1b93c0847a6aa982f62c8e539d04337
Signed-off-by: Rishabh Dave <ridave@redhat.com>
2 files changed